This invention relates to electrical DC-to-DC converters and more particularly to such circuitry for converting an input voltage of one polarity to an output voltage of the opposite polarity.
It is sometimes desirable to convert a source of unidirectional voltage of one polarity to a source of unidirectional voltage of the opposite polarity. This need arises, for example, when a semiconductor device is employed in an electrical circuit in which the only voltage source available is one of the wrong polarity.
An inductorless converter for accomplishing this function is disclosed in U.S. Pat. No. 3,970,871, issued July 20, 1976, Negative DC to Positive DC Converter, Ser. No. 443,587, filed Feb. 19, 1974, by the same inventor. The converter there includes a pair of transistors in a quick-setting astable multivibrator circuit that is powered by a DC voltage source of one polarity and which drives two pairs of transistors 81, 82 and 90, 98 comprising power switches. Capacitor means is connected across one pair of switching transistors for producing a DC voltage of the opposite polarity. Transistor subcircuits 87 and 99 are employed to reduce the reset time of switching transistors 81 and 98. An object of this invention is the provision of a more economical and simplified voltage converter circuit for accomplishing a similar function.